title: Effect of rhBMP-2 sustained-release nanocapsules on the ectopic osteogenesis process in Sprague-Dawley rats.
abstract: OBJECTIVE
  To explore the effect of sustained-release recombinant human bone morphogenetic protein-2 (rhBMP-2) on ectopic osteogenesis in the muscle pouches of rats through preparing rhBMP-2 sustained-release capsules by wrapping morphogenesis protein bones-2 (BMP-2) using chitosan nanoparticles, and compositing collagen materials.
  
  
  METHODS
  Twenty four Sprague-Dawley rats were randomly divided into four groups with six rats in each group, that is Group A (control group), Group B (only treated with collagen), Group C (rhBMP-2+collagen treated group) and Group D (rhBMP-2/cs+collagen treated group). The composite materials for each group were implanted in the bilateral peroneal muscle pouches in rats. The peroneal muscles were only separated without implanting any materials in control group. Rats were sacrificed 2 weeks and 4 weeks post treatment and samples were cut off for general observation, Micro CT scans and histological observation.
  
  
  RESULTS
  General observation showed no new bone formation in Groups A and B mice, while new bones were formed in Groups C and D mice. Two weeks after treatment Micro CT scans showed that The bone volume fraction (BVF), trabecular thickness (Tb.Th), bone mineral density (BMD) in Group C mice were all higher than that in Group D (P<0.05). At the fourth week, the BVF, Tb.Th and BMD were significantly higher than that at the second week (P<0.01).
  
  
  CONCLUSIONS
  The slow-release effect of rhBMP-2/cs sustained-release capsules can significantly promote ectopic osteogenesis. Its bone formation effect is better than that of rhBMP-2 burst-release group.
authors.affiliation: Department of Oral & Maxillofacial Surgery, First Affiliated Hospital, Jinan University, Guangzhou 510630, Guangdong, P.R. China.
authors.forename: Ren-Fa
authors.initials: RF
authors.lastname: Lai
authors.forename: Ze-Jian
authors.initials: ZJ
authors.lastname: Li
authors.forename: Zhi-Ying
authors.initials: ZY
authors.lastname: Zhou
authors.forename: Zhi-Qiang
authors.initials: ZQ
authors.lastname: Feng
authors.forename: Qing-Tong
authors.initials: QT
authors.lastname: Zhao
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000494:pharmacology*; D003094:Collagen / Q000494:pharmacology; D003692:Delayed-Action Preparations / Q000494:pharmacology; D004337:Drug Carriers / Q000494:pharmacology; D036341:Intercellular Signaling Peptides and Proteins; D018482:Muscle, Skeletal; D053769:Nanocapsules; D010012:Osteogenesis / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000494:pharmacology; D023822:Tissue Engineering / Q000379:methods*; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D055114:X-Ray Microtomography
chemical_list: C525720:Bmp2 protein, rat; D055396:Bone Morphogenetic Protein 2; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D036341:Intercellular Signaling Peptides and Proteins; D053769:Nanocapsules; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2; D003094:Collagen
keywords: BMP–2; Chitosan nanoparticles; Ectopic osteogenesis; Micro–CT; Polymeric drug–loading sustained–release capsules